1. Field of the Invention
The present invention relates to the field of packaging technology for fiber optics communication devices, and particularly for optical fiber feed-through the package body that provides hermetic sealing of optical devices.
2. Description of Related Art
Fiber optics transmission is now a common platform for transporting voice, data, and images. As the demand for data carrying capacity continues to increase, optical companies are finding techniques to utilize the bandwidth of existing fiber-optic cable more efficiently and increasing the performance of optical devices. The performance of optical devices is sensitive to its operational environment, such as humidity and pressure. Optical devices typically require a tight sealing package, i.e. hermetic sealing package, to prevent moisture or any other gas passing through, thereby ensuring stable performance of the optical devices during their life span. Fiber optics devices also require a package to have a mechanism in place to prevent optical fibers from mechanical damages arising from, for example, pulling or bending. Another desirable feature is to make an optical fiber feed-through removable because it is often necessary to re-open an optical device for rework or modification, particularly between the integration process step and the final test step.
A conventional sealing optical fiber solution uses an epoxy-type material to fill the pore in optical fiber holes and baking the package at an elevated temperature until the epoxy dries. However, this conventional solution is inadequate in meeting hermetic sealing requirements, particularly for an optical fiber with protective plastic coating. The gap between a plastic coating and a glass core also frequently fails to prevent moisture to pass through. To overcome this problem, an optical fiber may be coated with a metal film and then seal the package with epoxy. Still, this approach is difficult to implement for a large scale assembly operation. Accordingly, it is desirable to have a hermetic seal feed-through assembly that addresses these needs.
The invention provides an optical package assembly that is sealed hermitically with one or more feed-throughs with a mating ferrule. The ferrule has a head and a body, where the head in constructed in a conical shape and the body is constructed in a cylindrical shape. The ferrule is compressed at the head to hermitically sealed the fiber to the optical package and is compressed at the body to hold the fiber in place. It is apparent to one of ordinary skill in the art that the expression of compressing the ferrule can also be described as mechanically deformed the ferrule, or by other similar or equivalent terms.
Advantageously, the present invention provides a strong resistance to external force, compact in package height, simple to install, simple to remove, and applicable to fibers with plastic coating.